1. Technical Field
The present disclosure relates to a battery, a battery system, and a method for detecting state of battery.
2. Related Art
In recent years, batteries (storage batteries) such as secondary batteries and capacitors have been developed and have been widely used as power supplies for various electric appliances. The demands for increases in capacitance of batteries, that is, the demand for increases in output have been increased with the increase in expectation for the use of the batteries as power supplies for large hybrid electric vehicles and electric vehicles.
In order to meet such demands, schemes have been devised which increase the energy densities of electrode materials used in a battery and allow high-density packaging of the electrode materials. However, as the energy densities of the electrode materials increase, the frequency that abnormal heating occurs increases and thus the risk of the battery increases. Therefore, safety measures for safe use of the battery are more important.
The safety measures in the past include precise control over charge/discharge to/from a battery for preventing overdischarge or overcharge, for example, and processing on an electric circuit therein of using a thermistor to measure the temperatures of the battery and turning off the circuit when the battery is overheated. (for example, refer to patent document 1 below).    Patent document 1: Japanese Unexamined Patent Application Publication No. 2000-048861